1. Field of the Invention
This invention relates to card frames, and is more particularly directed to the packaging and erection thereof.
2. Description of the prior art
A `card frame` (also known as a `sub-rack`) is a kind of frame structure used to house electrical circuitry mounted on `cards` which, for example, comprise circuit boards, for instance printed circuit boards, mounting circuit components. A typical card frame comprises a pair of side plates spaced apart by generally horizontally extending cross rails secured at their ends to the side plates, the cross rails typically mounting card guides for receiving the cards and connectors for making electrical connections to the cards.
Card frames are often manufactured by specialist manufacturers and supplied by them, in kit form, to the end user. The end user is typically an electronics manufacturer who manufactures circuit cards and erects or assembles the card frame from the kit into a particular form suited to the precise requirements of the end product to be assembled from the cards and card frame.
An advantage of the card frame is that once the basic structure thereof has been erected by securing together the side plates and at least some of the cross rails, the structure acts to some extend as its own jig for further assembly purposes. However, the initial assembly of the basic structure can be difficult since it tends to be a job for which two hands are not enough.